If we define a Complete Ancestors Tree (CAT) as the one where in a given generation ‘n’, all ancestors are accounted for. For 10 generations, this is 2046 ancestors (sum of 2^n). CAT’s are not common goal in genealogy, as most people follow their ancestry ‘vertically’ along specific lines, rather then ‘horizontally’, trying to account for every person in their ancestors’ tree. Here an attempt will be made to identify profiles where this has been achieved. This must be documented and sourced - real people, real records. If enough trees of this type are identified, the information might provide a basis for further research in population statistics and in particular collapsing trees.

Apart from ‘completeness’ measure, we can also define Highest Different Ancestors (HDA) number as a separate measure to represent those trees which might not be complete but their ancestors count is very high.

Graph legend

Completeness of the tree is presented on a donut graph, with detailed description provided in Visualising common ancestor project. The little black circle on the graph indicates that the ancestor appears in multiple places in the tree. For this purpose option ‘Common ancestors for 1 person’ is used, where every group of ancestors which is repeated is marked in separate colour. For example if we know that two ancestors were related their common ancestors will be marked in a separate colour including all of his ancestors (referred to as Group ‘n’). Missing data for each generation will be listed in the following format gen n-> x (out of 2^n), ie x is the number of missing ancestors in each generation. For each graph, additional information is provided, added as 2 separate comments on the image. One comment contains listing for each generation, for example: Generation: 8(256) Diff Ancestors: 178 Known Ancestors: 250 Missing Ancestor: 6 where Known ancestros represent number of different ancestors for that particular generation, Missing ancestors - number of those missing. Second comment lists all ancestors without parents to make it easier to find missing bits to complete the tree.

How to participate

The easiest way to test completeness of the tree using my program, so if you think a particular profile is close to this definition, add them to this project, and I can test it. Keep in mind, that regardless of the fact that we have 1024 ancestors in 10th generations, due to same ancestors appearing multiple times, this number can be as low as 400 and the tree could still be complete. If your tree contains private profiles, it will have to wait until my software is ready.

Most complete family trees for Croatia are from from Podgora, Makarska, this is where we started using Geni. Written reliable records for Podgora exist from 1621, and cover complete periods 'till today. As the area was isolated geographically (narrow strip of land with Adriatic sea on one, Biokovo mountain on the other side) and politically (border with Ottoman empire was only 20km? away for few hundred years) people did not move much. There was no much change in population; except for people migrating to New World countries during hard times (the estimate is that there are more people with Podgora ancestry in New Zealand then anywhere else in the world).